change repo structure; modify readme

tensorneat/algorithm/neat/gene/node/base.py

@@ -0,0 +1,12 @@
+from .. import BaseGene
+
+
+class BaseNodeGene(BaseGene):
+    "Base class for node genes."
+    fixed_attrs = ["index"]
+
+    def __init__(self):
+        super().__init__()
+
+    def forward(self, attrs, inputs):
+        raise NotImplementedError